Reversible valve-gear



No. 6l8,068. PatentedA lan. 24, |899. A. G. DIVET.

REVERSIBLE VALVE GEAR.

(Application med Mar. 25, 1898.)

Zzzsses.

WAM

NTED STATES PATENT OFFICE.

ARTHUR G. DIVET, OF WAI-IIETON, NORTH DAKOTA.

REVERSIBLE VALVE-G EAR.

SPECIFICATION forming part of Letters Patent No. 618,068, dated J'anuary 24, 1899. Application filed March 25,1898. Serial No. 675,101.(No model.)

.To all whom, it may concern.-

Be it known that I, ARTHUR G. DIVET, a citizen of the United States,residing at Wahpeton, in the county of Richland and State of NorthDakota, have invented certain new and useful Improvements in ReversibleValve- Gears; and I do hereby declare the following to he afull, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

Hy invention has for its principal object to so improve enginevalve-gears that they may be readily reversed 5 but it has also for itsobject to so improve said valve-gear that the engine may be started andstopped by shifting the eccentric thereof.

To the ends above indicated my invention consists of the novel devicesand combinations of devices hereinafter described, and deiined in theclaims.

The preferred form of my invention is illustrated in the accompanyingdrawings,wherein like numerals indicate like parts throughout theseveral views.

Figure 1 is a diagram view, partly in plan and partly in side elevation,some parts being sectioned and others broken away, illustrating theaction of my improved valve-gear on the slide-valve which controls theadmission and exhaust of steam or air to and from the cylinder. Fig. 2is a view, partly in front elevation and partly in vertical section, onthe line c2 0:3 of Fig. l. Fig. 3 is a view corresponding to Fig. 2, butwith more of the parts shown in section and with the eccentric andcam-block for controlling the same occupying different positions, andFig. 4 is a detail view, principally in plan, but partly in horizontalsection and with some parts broken away, illustrating means for shiftingthe camblock.

1 indicates the crank-shaft of the engine, mounted in bearings 2 andprovided at one end with the crank-disk 3, having the Wristpin 4. Thefly-wheel or belt-engaged drivingpulley is not shown,but would becarried by the end of the crank-shaft, which is broken away.

5 indicates the steam-chest of the engine, provided with ports 6.

.7 indicates the slide-valve, which works in the steam-chest 5 andcooperates with the ports in the ordinary manner. The valve 7 isprovided with a stem 8, which works outward through a stuffing-box 9 inthe end of said steam-chest 5.

To the intermediate portion of the crankshaft 1 a pair of longlongitudinally-extended keys 10 are secured by means of suitablekeyseats and a pair of collars 11, held in place on said shaft byset-screws 12. Sliding on the shaft 1 and keys 10 is a cam-block 13,which is caused to rotate with said shaft. The head of this cam-block 13is provided wit-h an annular groove, in which a shipper-collar 14 works,and it is provided with the cam-actin g extension 15, that isrectangular in cross-section and extends at an angle to the axis of theshaft. Longitudinal slots 16 extend through the inclined faces of thecam-block 15, and diametrically-extended pins or fingers 17 project fromthe keys 10 and work through said slots 16. The eccentric 18 is providedwith a rectangular perforation that iits the cam portion of saidcam-block. This eccentric 1S is held in a plane at a right angle to theaxis of the shaft 1, and while it is free to move in the plane in whichit is set it is held against movement longitudinally of the shaft bymeans of the projecting pins or fingers 17, which work indiametrically-extended seats in said eccentric. lVith the constructionshown, wherein the diametrically-projected pins or fingers 17 are formedintegral with Jthe keys 10, the keyways for the said keys should be runto one end of the shaft 1, or some other provision should be made whichwould permit the parts to be readily put together. It is of courseevident that the diametricallyprojecting pins or iingers might bedriven, screwed, or otherwise secured in place after the other partshave been properly assembled and also that one or more of thesediametrically-projecting pins or fingers might be directly secured tothe shaft itself.

A two-part eccentric-strap 19 works on the eccentric 13 and is providedwith an arm 20, the free end of which is pivoted to the outer end of thevalve-stem 8.

. The cam-block 13 15 is adapted to be shifted at will and held whereset by means of a suitable hand-operated device, which, as shown,involves a bell-crank 21, one arm of which is ICO pronged and pivotallyconnected to the ring or collar I4, as shown at 22, and the other arm ofwhich is connected to a hand piece (not shown) by means of a link 23 orother suitable connections.

As previously stated, it is the salient object of my invention toprovide an improved reversing device for reversing the valve-gear andcausing the same to reverse the action of the engine. Figs. l and 2illustrate one position of the eccentric and Fig. 3 illustrates anotherextreme position of the same. It will be noted that in Fig. 2 saideccentric is thrown to a point of eccentricity to its axis of rotationdiametrically opposite to the point of eccentricity which is given inFig. 3. This, of course, will `give the said eccentric a reversedaction. As is evident, the above movement of the eccentricV is caused bymoving the cam-block longitudinally on the crankshaft. The extrememovement of the camblock Will move said eccentric and its strap from thepositions indicated by full lines into the positions indicated by dottedlines in Fig. l. It is, however, very important to note that in passingfrom one extreme position to another the eccentric is moved to anintermediate point, Where it stands concentric to its axis of rotation,or, in other Words, to the axis of the shaft l. In this position it isevident that the valve 7 will not be moved by the rotation of thecrank-shaft l and eccentric. In this case the engine will soon bebrought to a stop or standstill by the continued application of steam toone end of the cylinder. Hence it is evident that this movement of theeccentric may be utilized to start and stop the engine.

It Will of course be understood that I do not limit myself to theparticular construction above described. On the contrary, it is thoughttobe obvious that my invention is capable of a large range ofmodification.

The expression eccentric and strap is used broadly in this specificationand in the claims and is intended to include a crank and pitman as Wellas the ordinary eccentric and strap.

IVhat I claim, and desire to secure by Letters Patent of the UnitedStates, is as follows:

l. In a valve-gear, the combination With a shaft, of a cam-block mountedto rotate with but free to move axially on said shaft, an eccentricmounted on said cam-block and rotatable therewith, and aradially-projecting guide pin or finger carried by said shaft andengaging said eccentric and operating to hold the said eccentric againstmovelnent longitudinally of the shaft, but permitting the same to movetransversely thereof, substantially as described.

2. In a valve-gear, the combination with a shaft, of a cam-block carriedby but mounted to slide on said shaft, diametrically-projected pins orfingers Working through longitudinal slots in said cam-block, aneccentric mounted on said cam-block and held for movement in a givenplane by said projecting pins or fingers, an eccentric-strap Working onsaid eccentric, and means for moving said cam-block at Will,substantially as described.

In testimony whereof I affix my signature in presence of two Witnesses.

ARTHUR G. DIVET.

Titnessesz J. A. SLATTERY, CHAS. E. IVoLF.

